Electrical machines include both electric motors and electric generators. In recent years, high efficiency electric motors have become desirable to meet the challenges of providing power without the usage of fossil fuel sources, for example in hybrid and electric vehicles. Interior permanent magnet (IPM) motors have become popular due to their high efficiency performance, as IPM electric machines have become increasingly efficient synchronous motors due to advances in high-energy permanent magnet technology, smart inverters, and digital controllers. IPM electric machines have magnets built into the interior of the rotor. The rotor is rotatable within a stator which includes multiple windings to produce a rotating magnetic field in the frame of reference of the stator.